My 2008 Mazda CX-7 (144,000 miles) check engine light came on 3 weeks ago. No big deal at the time, slight hesitation when accelerating at highway speeds but no other apparent issues. A week after that the car had trouble starting, the engine would turn on but immediately turn back off, which also caused a semi strong gasoline smell (misfiring?).  It would only stay on if you pressed on the accelerator and stayed above 2500 RPM for around 5 seconds, I was able to drive it with not much hesitation after that. Letting it idle without pressing the accelerator would cause it to turn off after 8-10 minutes, it would creep right above 1500 RPM and then die. I took it to an auto parts store and was told it was an P-2177 error (System too lean off Idle - Bank 1).

Since then, starting the car has become a bigger hassle, at times you have to press down on the accelerator for ~10 seconds at above 2500 RPM and even then sometimes the car stalls as soon as you let go of the gas. I am still able to drive it, with little to no problems, only the slight hesitation at higher speeds.

Now in the present I have cleaned the MAF sensor and that didn't really help. Looking online at other solutions seem to be a faulty air fuel ratio sensor (O2 sensor), clogged intake ports, faulty fuel pump, fuel pump filter etc. Their doesn't seem to be a clear way on how to clear up this code/issue.

What should I do at this point? I am open to try out any of the solutions above but I just want to get some input before proceeding.

Thank you.